Prepare the Aji sauce by blending the cilantro, mayo, olive oil, parmesan cheese, white vinegar, ¼ lime, water, jalapenos, and 2 cloves of garlic in a food processor until smooth. Season to taste with more lime, salt, pepper, and sugar.
Prepare the Lomo Saltado ingredients: Cut the ribeye or filet mignon into large cubes and season with salt and pepper. Chop the red onion into large pieces. Chop the plum tomato into large pieces, removing the seeds. Mince 1 clove of garlic.
Prepare the sauce for the Lomo Saltado by mixing the Maggi seasoning, fish sauce, sugar, and water.
Fry the French fries in batches, double frying them to make them extra crispy.
In a hot pan or wok, sear the beef cubes on high heat until browned on one side, then flip and add a bit of butter to finish cooking.
Remove the beef and add the minced garlic to the pan, cooking for 30 seconds. Then add the chopped onions and tomatoes, cooking on high heat to char them slightly.
Add the sauce mixture to the pan and let it cook briefly, then add the seared beef and crispy French fries. Toss everything together quickly until the sauce is absorbed.
Serve the Lomo Saltado with rice and the Aji sauce on the side, squeezing fresh lime juice over the top.
